Yuan Xiaolei, Wu Yueshen, Jiang Bei, Wu Zishan, Tao Zixu, Lu Xu, Liu Jie, Qian Tao, Lin Haiping, Zhang Qiao
School of Chemistry and Chemical Engineering, Nantong University, 9 Seyuan Road, Nantong, Jiangsu 226019, China.
Department of Chemistry, Yale University, West Haven, Connecticut 06516, United States.
ACS Appl Mater Interfaces. 2020 Dec 16;12(50):56642-56649. doi: 10.1021/acsami.0c19031. Epub 2020 Dec 7.
The production of CO from the CO reduction reaction (CORR) is of great interest in the renewable energy storage and conversion, the neutral carbon emission, and carbon recycle utilization. Silver (Ag) is one of the catalytic metals that are active for electrochemical CO reduction into CO, but the catalysis requires a large overpotential to achieve higher selectivity. Constructing a metal-oxide interface could be an effective strategy to boost both activity and selectivity of the catalysis. Herein, density functional theory (DFT) calculations were first conducted to reveal the chemical insights of the catalytic performance on the interface between metal oxide and Ag(111) (MO/Ag(111)). The results show that the COOH intermediates can be more stabilized on the surfaces of MO/Ag(111) than pure Ag(111). The hydrogen evolution reaction on MO/Ag(111) can be suppressed due to the significantly higher Gibbs free energy for hydrogen adsorption (Δ), thereby enhancing the selectivity toward CORR. A series of MO/Ag composites with the unique interface based on the DFT results were then introduced though a two-step approach. The as-obtained MO/Ag catalysts boosted both the CO activity and selectivity at a relatively positive potential range, especially in the case of MnO/Ag. The reduction current density on the MnO/Ag catalyst can reach 4.3 mA cm at -0.7 V (vs RHE), which is 21.5 times higher than that on pure Ag, and the overpotential of CO to CO (390 mV) possesses is much lower than that on pure Ag NPs (690 mV). This study proposes an effective design strategy to construct a metal-oxide interface for CORR based on the synergistic effect between metals and MO.
一氧化碳还原反应（CORR）生成一氧化碳在可再生能源存储与转换、中性碳排放以及碳循环利用方面具有重大意义。银（Ag）是对电化学一氧化碳还原为一氧化碳具有活性的催化金属之一，但该催化反应需要较大的过电位才能实现更高的选择性。构建金属 - 氧化物界面可能是提高催化活性和选择性的有效策略。在此，首先进行了密度泛函理论（DFT）计算，以揭示金属氧化物与Ag(111)（MO/Ag(111)）界面催化性能的化学见解。结果表明，COOH中间体在MO/Ag(111)表面比在纯Ag(111)表面更稳定。由于氢吸附的吉布斯自由能（Δ）显著更高，MO/Ag(111)上的析氢反应可以得到抑制，从而提高了对CORR的选择性。然后通过两步法引入了一系列基于DFT结果的具有独特界面的MO/Ag复合材料。所制备的MO/Ag催化剂在相对正的电位范围内提高了一氧化碳活性和选择性，特别是MnO/Ag的情况。MnO/Ag催化剂在 -0.7 V（相对于可逆氢电极，RHE）时的还原电流密度可达4.3 mA cm，比纯Ag高21.5倍，并且一氧化碳生成一氧化碳的过电位（390 mV）远低于纯Ag纳米颗粒（690 mV）。本研究基于金属与MO之间的协同效应，提出了一种构建用于CORR的金属 - 氧化物界面的有效设计策略。
